rare earth

American  

noun

Chemistry.

1. the oxide of any of the rare-earth elements contained in various minerals.

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rare earth British  

noun

1. any oxide of a lanthanide

2. Also called: rare-earth element.  another name for lanthanide

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Etymology

Origin of rare earth

First recorded in 1875–80

Example Sentences

“The Western rare earth sector stands at a critical inflection point, as governments and strategic industries urgently seek reliable sources of critical rare earths — particularly scarce heavy rare earths.”

From MarketWatch • Apr. 20, 2026

The Tanbreez project holds 45 million tons of rare earth hard rock deposits, with a pilot plant program starting in May.

From Barron's • Apr. 17, 2026

Critical Metals stock skyrocketed Friday after the miner took a big step toward tapping Greenland’s rare earth deposits.

From Barron's • Apr. 17, 2026

The National Park Service and an Australian company are at odds over an old Mojave Desert gold mine, where the company is seeking to extract rare earth minerals.

From Los Angeles Times • Apr. 15, 2026

The rare earth metals are found in the minerals gadolinite, samarskite, fergusonite, euxenite and cerite.

From Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 7 "Equation" to "Ethics" by Various